1. Technical Field
This invention relates to the field of preservation of tissues after removal by surgery for preserving the tissues for subsequent histopathological examination and tissue banking as well as for transplantation of scientific purposes.
2. Description of the Background Art
The standard use of formalin (formaldehyde), both as a preserver and fixative for histological processing, is encountering increasing criticisms because of toxicity and environmental concerns. Moreover, the declaration recently issued by the International Agency for Research on Cancer, (International Agency for Research on Cancer (2006), Monographs on the evaluation of Carcinogenic Risk to humans. (IARC, Vol. 88) Lyon, France), which classified formaldehyde as a Class 1 carcinogen has definitely increased the request by health authorities, technicians and practicing pathologists to entirely avoid or at least substantially reduce contact with formalin. Such requests contrast with the considerable advantages offered by this reliable fixative. Although it should be acknowledged that in modern pathology laboratories visitors are not any more confronted with the vapors of a strong scent, since formalin processing is mostly carried out under aspiration hoods, a critical passage is still existent due to the transfer of tissues from the surgical theatre to the pathology lab. Apart from small biopsies which are directly collected into pre-filled containers and cause no concerns, problems are encountered with the immersion of large specimens and organs into large boxes to be filled with formalin.
Such problems may be summarized as follows:                1) Plastic containers are large and relatively heavy while on occasion spilling may occur.        2) Immersion into formalin prevents the collection of fresh material for tissue banking. Fixation starts, but only at the periphery. Discoloration occurs while a delay in the transfer to pathology labs is somehow justified by the fact that “the tissue is already in formalin”.        3) Nurses at the surgical theatre become increasingly concerned for toxicity and cancerogenicity issues since the fluid has to be managed freely and not under hood.        4) When the container arrives at the pathology lab, its opening, removal of the specimen and reduction of the latter constitutes a major cause of diffusion of formaldehyde vapors.        
In more recent years, alternatives to formalin (formaldehyde) have been proposed. From WO 2004/093541 A1 a formaldehyde-free, non-alcoholic tissue preservative composition is known which comprises ethanedial and a polar aprotic solvent in aqueous solution. Further known tissue preservatives compositions which do not contain formalin, contain glutaraldehyde or alcoholic solvents or compounds such as acetic acid which pose hazardous waste disposal problems and potentially are irritants to persons exposed to tissue preservative compositions in their work.
It is object of the invention to provide a technology to satisfactorily preserve human and animal tissues after removal from the body to prevent the growth and propagation of microbes and autolytic processes without the need of using tissue preserving agents which are toxic and environmentally hazardous and thus absolutely dangerous for people directly involved in resection, transplantation and examination of tissues.